X-ray photography



Patented Dec. 7, 1926.

UNITED STATES PATENT OFFICE.

$03511? EQGERT, OF BERLIN-FRIEDENAU, AND PAUL MENDELSSOHN-BARTHOLDY, OFBERLIN, GERMANY, ASSIGNORS TO Gr. FAEBENINDUSTEIE AKTIENGESELLSGHAFT,

O11" FRANKFURT, GERMIANY.

X-RAY PHOTOGRAPHY.

Ne Drawing. Application filed December 24,

This invention relates to an improvement in the art oi? taking X-rayphotographs. Normally a certain period 01'. exposure is necessary inorder to a secure a. hotograpli oi a desired intensity; it is not,however, always convenient to give prolonged exposures, and in manycases it is important to reduce the time oi" exposure considerably. lheperiod of exposure may be decreased by taking advantage of the smallloss in energy which X-ra s suffer in passing through the material ofwhich photographic plates and films are usually composed. Thus it ispossible to expose simultaneously to the action or X-rays a number ofseparate, su 'ierimposed photographic plates or films. It the time ofexposure be decreased below that usually necessary, there is obtained anumber of identical negatives, all strongly under-exposed. When,however, these negatives are coincidently superimposed and held to thelight, there is obtained a single, and extraordinarily effectivepicture.

According to the i vention the X-ray photograph is taken on a packet ofphotographic films each coated with suitable photographic emulsion. Thepacket may comprise any suitable number of the films held togetherclosely and so firmly that they cannot suller any relative displacementduring the exposure. Instead ot forming the film packet from severalindividual films held in position .ior instance by frames. clips,gumming at the edges, a film of suitable dimensions to produce thedesired packet may be folded, in which case the various elements of. thecomposite picture Form a single piece, which can. be unfolded tordevelopment and suli sequently refolded to produce the compositepicture. It, however. the packet is loaned of single films, they areseparated from each other for de velopment after the exposure and afterdevelopment united again by any suitable holdingdeviee to produce acomposite photograph in a very handy form.

In addition to films sensitive to light the packet may also includeintensifying plates used in X-ray photography. The films and theintensifying plates may be distributed in the packet in a suitablesuccession.

Having now described our invention What We claim is 1823. Serial No. andin Germany March 21, 1923.

the pictures in the exact relation in which the exposures were made.

'. in a method oi taking- X-ray photo- .pllS, the steps which consistsin underaosing a plurality of films as a unit in superimposed relationand placing the films er development in exactly the same superposedrelation in which they were during the exposure.

3. in X-ray film package capable when fu l Y :ted to a relatively shortexposure of providing the equivalent ot a single fullyerzpos :l film,said package comprising a plurality of closely superposed filmsrestrained against relative displacement, the number of films beari rsuch inverse ratio to the degree of per rssible undereirposurc of theaaclrage that when the separate strongly underexposcd films aredeveloped and superposed the assembled films give substantially thecfiect of a single fully-exposed film.

4. A plurality oi sharply underexposed Xo'ay films resulting from asingle exposure in closely superposed relation, the number orunderexposed films having such relationship to the degree ofunderexposure or each film that the assembled films give an efi'ectsubstantially equivalent to that of a single fully-exposed film.

5. A plurality of sharply undcrexposed X ray films in superposedrelationship, said films resulting from a single and relatively shortexposure ol the films in closely superposed relation. the number of thefilms and the degree of underexposure of the several films being sochosen that the composite effect of the asscmliiled films is sub--stantially the equivalent of that of a single fully-exposed film.

In testimony whereof we afiix our signatures.

Dr. JOHN EGGERT. PAUL MENDELSSOHNBARTHOLDY.

